Author Topic: No more GM barrels in Mrods? (Read 13943 times))

K.O. · « **Reply #80 on:** July 09, 2019, 05:00:03 AM »

I estimated my Mrod slugging it at the Breech and the muzzle and estimated 250 Bore, 252 groove... at the choke it is .2495... Fowler cheap Micrometer

http://www.fowlerprecision.com/Products/Vernier-Micrometers/0-1-Outside-Inch-Micrometer-52-229-201.html

BBT are best sized to either .2495-.250 so I think I got groove size right... checked a couple .250 drill bits with the mic and they did not fit the muzzle... My other .25 slugged the same .250 /.252 at the Breech and is tighter at the muzzle /choke...think groove is around .2483-.2485 ish...

I think Fowler has pocket comparators..?

Machinist · « **Reply #81 on:** July 09, 2019, 10:35:30 AM »

No problem Andy.

This particular comparitor actually has a resolution of 10 millionths. I just went and looked at it. That should be good enough.

Steve

Machinist · « **Reply #82 on:** July 09, 2019, 10:41:58 AM »

Hey Kirby,

It's good to see the dimensions of another barrel. Quite a bit different than mine.

Maybe Fuzzy or someone else can post their dimensions.

Thanks,
Steve

FuzzyGrub · « **Reply #83 on:** July 09, 2019, 10:47:43 AM »

Quote from: Machinist on July 09, 2019, 10:41:58 AM

Maybe Fuzzy or someone else can post their dimensions.

I'll be able to do twist rate but have nothing capable of measuring lands and grooves.

I appreciate the detail provided.

Machinist · « **Reply #84 on:** July 09, 2019, 01:49:36 PM »

If you have a 25 Mrod barrel and are willing to check the inside diameter at the muzzle and breech, I can send you some homemade aluminum rods that range from .245"-.250"

If you would rather have delrin, I can do that.

Just carefully check the bore, and then post the results.

Steve

FuzzyGrub · « **Reply #85 on:** July 09, 2019, 01:58:45 PM »

Quote from: Machinist on July 09, 2019, 01:49:36 PM

If you have a 25 Mrod barrel and are willing to check the inside diameter at the muzzle and breech,
I can send you some homemade aluminum rods that range from .245"-.250"

If you would rather have delrin, I can do that.

Steve

WOW! Thanks, I appreciate it.

Info has been IM'ed to you.

K.O. · « **Reply #86 on:** July 09, 2019, 04:33:05 PM »

Mine are the old barrel 2014 and 2016... just to be clear...

I need to look not sure where I put it but have a section of the Muzzle end of a choked Airforce L.W. barrel Owen sent it to me when he cut it off... If you want it to look at under the scope am willing to send it to you... like he did for me...

pic in reply #128 https://www.gatewaytoairguns.org/GTA/index.php?topic=110616.120
reply #79 has Mrod and XL 725 and L.W. muzzle pics https://www.gatewaytoairguns.org/GTA/index.php?topic=110616.60

looks like the new .25 Mrod barrel is heavily choked 6 Land/Groove and about 25% .255 land 75% .251 groove... so the .254 BBT may be a better choice now... also with a slow twist a probable no for the 51g .25 BBT... unless the the mold is decked removing the removing tail..

Machinist · « **Reply #87 on:** July 09, 2019, 08:05:08 PM »

Kirby

How many grooves in the 25 GM barrel?

The piece of barrel I checked on the comparator was only .115" thick. I don't need a long piece. I figured the shorter the better. I think the ends need to be square to the bore though. If you find it, sure I could measure the land width and other stuff. Compare it to the crosman. If you send me a 2 inch piece, would it be alright if I cut off .150" or so and then returned it to you?

When I got this crosman 25 barrel, I did a quick check of the bore. A .249" pin gage would not go in the breech end. A .248"pin did go. It fit pretty nice, so I figured cool, a .248" bore.

But a few days ago, when I faced off the chamber a little at a time, I saw that there was absolutely no leed, just a nice sharp burr from the factory. That's what my pin gages hit. When I got rid of the burr, a .250" rod slid right into the bore.

If you want some homemade gages .245" - .250" I could send them to you.

Steve

porkchopexpr3ss · « **Reply #88 on:** July 10, 2019, 08:24:35 AM »

shame. maybe thats why my 2018 .25 mrod shot the bbt slugs poorly. any barrel options for a mrod slug gun?

HunterWhite · « **Reply #89 on:** July 10, 2019, 08:49:53 AM »

Oh man, this is looking kind of sad. I hope this doesn't bring the end of a good run for a great rifle.
I have a 25 that is supposed to be a GM. I will try to measure it this weekend when I get back home.

kkarmical · « **Reply #90 on:** July 11, 2019, 09:48:03 PM »

They're still showing in stock on Hill website

https://hillairgun.com/products/m-or-a-25-rifle-barrel/

FuzzyGrub · « **Reply #91 on:** July 11, 2019, 10:18:10 PM »

Quote from: kkarmical on July 11, 2019, 09:48:03 PM

They're still showing in stock on Hill website

https://hillairgun.com/products/m-or-a-25-rifle-barrel/

By the note at the end of the add, I’d say it is a crosman barrel.

K.O. · « **Reply #92 on:** July 12, 2019, 03:51:15 PM »

Steve been looking for the L.W. muzzle bit I know I have... a touch here and there but have been exhaustingly busy...framing and sheathing with a road trip for a friend(that just happens to have a by .001 zz class set of pins) mixed in...So have not been able to find it yet... Thought I had put it in my misc barrel area... so I hope I find it soon...doing the roof today and maybe some wrap and siding...my road trip Bud is helping with the window in about an hour...

Soon will have more time to look... know I have it unless my son thru it out...

I think we need more high quality educational pics to explain the plus/minus of different types of rifling and the ability to know at least that Mrod 25 Barrel is made about a certain spec...Others should be close...

So not giving up on finding it yet...

do appreciate the offer but have access to a set of pins... I have mainly used them to make sure my Folwler mic is accurate...

right now just annoyed and embarrassed with my forgetfulness... could have sworn I put it in the misc parts box...or with my barrel collection...

Machinist · « **Reply #93 on:** July 12, 2019, 06:49:02 PM »

Don't worry about it Kirby. Thanks for looking though. Sounds like you need to sit in the shade and have a gallon of homemade iced tea, not beat yourself up. I've misplaced things the size of bowling balls.

Absolutely, it would be great to hear from a barrel expert. It kinda seems like making barrels is a black art in some ways. But simple things like being .001" or .002" oversize is easy to find. If you make lots of parts, but don't, or can"t check every one, a few bad ones will go out the door.

I was gonna send you a 1/4" dowell pin. They are pretty accurate and hardened. Can sorta check a mic with that if that's all you have. I might have an extra standard laying around too. If I can find it. It's probably behind the bowling ball.

It seems like the .25 cal GM barrels have 10 grooves, and the .25 cal Crossman barrels have 6 grooves. Pretty easy to count the grooves.

Steve

K.O. · « **Reply #94 on:** July 12, 2019, 11:46:24 PM »

touch more to do... window is waiting till tomorrow... 80* all day but muggy at 50% humidity (recent t storm) 90* now... getting to close to being 60 for this..

Back in a while...

moorepower · « **Reply #95 on:** July 13, 2019, 12:18:16 PM »

Quote from: YEMX on July 03, 2019, 02:07:31 PM

Quote from: moorepower on July 03, 2019, 01:44:03 PM
Green Mountain has never sold individual barrels...

They offer barrels and blanks, sold to the individual... It's literally on their website... I'm confused as to why you say this...

I know we're not privy to the contract between crosman and GM, but I kinda feel like once you're contract is done, the product is good for sale on the open market- kind of like when a patent runs out. I'm sure I'm wrong, as I'm not a lawyer. But it makes sense to me.

I actually lis ted the prefits that were the exception in the same sentence. All other barrels they sell are unturned blanks.

kkarmical · « **Reply #96 on:** July 13, 2019, 02:39:41 PM »

Quote from: FuzzyGrub on July 11, 2019, 10:18:10 PM

Quote from: kkarmical on July 11, 2019, 09:48:03 PM

They're still showing in stock on Hill website

https://hillairgun.com/products/m-or-a-25-rifle-barrel/

By the note at the end of the add, I’d say it is a crosman barrel.

*NOTE: According to the last New .25 caliber Marauder RIFLE I purchased, it looks like Benjamin has changed their .25 caliber barrels. Instead of 10- lands and 10 grooves (which this barrel that is for sale from hill airgun has), to the barrels that are being sold with new .25 caliber Benjamin air rifles, that now have only 6- lands and 6- grooves.

Includes: 1- New .25 caliber GM barrel (10- lands and 10 grooves), paypal fees, and free fast Priority Mail shipping, within the USA

This is the note & item description from the Hill website, unless I am reading this incorrectly, he selling the old GM barrels.

Rick67 · « **Reply #97 on:** July 13, 2019, 02:54:46 PM »

Ken sir, Mr. Hill must have seen this thread and edited it.

I have seen the description before, and it did not state it being a GM barrel emphatically.

I think the inventory will not last for long as GM barrels are no more

msurf · « **Reply #98 on:** July 13, 2019, 07:59:15 PM »

Have been following this thread guys...thanks for the research. I just checked mine and I do, in fact have a 10 groove barrel. My Marauder was purchased in 2015.

PCPhack · « **Reply #99 on:** July 13, 2019, 08:08:38 PM »

I emailed Tim a few days ago asking if it was in fact a GM. He replied yes, and then I noticed that he updated the page.

Edit: I also ordered a few for some future projects. I would not wait to order one if you want one.

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No more GM barrels in Mrods?

Author Topic: No more GM barrels in Mrods? (Read 13943 times))